In recent years, primarily in the fields of an optical lens, a plasma display panel (PDP), a cathode tube display (CRT) and a liquid crystal display of such as a computer and a word processor, proposed is an antireflection film having an antireflection layer for improvement of transmittance and contrast and for decrease of mirrored images. As for an antireflection layer, it is effective to decrease optical reflection at the interface between an accumulated substance and the air by accumulating a few layers having suitable values of a refractive index and an optical thickness as an optical interference layer. As an optical interference layer, provided is a low refractive index layer in which such as SiO2 and MgF2 as a low refractive index material is utilized.
An antireflection film can be manufactured by a dry casting method or a coating casting method, however, a coating casting method is generally utilized with respect to an advantage of easiness and a low cost. Further, the antireflection film is generally provided with hard coat property to give capabilities of such as anti-scratch property, anti-abrasion property and chemical resistance, by forming a hard coat layer as an intermediate layer on a film substrate. A hard coat layer generally comprises a ultraviolet curable resin to give hard coat property, and a ultraviolet curable (meth)acrylate monomer having a (meth)acryloyl group is primarily utilized. Further, in a hard coat layer, a fluorine or silicone surfactant, which has a great effect to decrease surface tension of a coating solution, is utilized to give an even surface and to prevent surface defects such as repelling and missing. However, in a hard coat layer utilizing the aforesaid (meth)acrylate monomer together with a fluorine or silicone surfactant, there caused a problem of adhesion (blocking) of the surfaces each other and abrasion on a hard coat surface when a hard coat layer and a surface without a hard coat layer (such as a back coat layer) are accumulated or hard coat film is stored in a state of a wound roll form, for example, under an environment supposing a season of high temperature and high humidity of a summer; there caused a problem of generation of spotty unevenness without forming an even surface in the case of forming antireflection film by coating an antireflection layer on the hard coat layer having been suffered from blocking; or there caused a problem of decreased adhesion property of an antireflection layer when antireflection film is prepared by utilizing a fluorine or silicone surfactant in a hard coat layer. Thereby deterioration of a product value and productivity were induced and rapid solution thereof has been desired.
A technology of a vinylidene chloride resin type water-based coating agent containing such as hydrophilic inorganic powder is known as an anti-blocking agent (please refer to, for example, Patent Documents 1 and 2). However, a sufficient effect has not been achieved with respect to an anti-blocking effect, a coating behavior of a hard coat layer (surface defects such as repelling and missing) and adhesion property of an antireflection layer. In Patent Document 3, a technology to incorporate ionization radiation curable resin and a nonionic surfactant in a hard coat layer is disclosed. However, there is no description on a compound of this invention in the aforesaid document, and the aforesaid nonionic surfactant is difficult to achieve compatibility of an anti-blocking effect and adhesion property of antireflection layer.
Patent Document 1: JP-A 5-132645 (Hereinafter, JP-A refers to Unexamined Japanese Patent Application Publication No.)
Patent Document 2: JP-A 9-291250
Patent Document 3: JP-A 2004-114355